Beam splitting prism and photodiode receiving assembly with beam splitting function
By integrating beam splitting, focusing, and receiving functions using a beam splitter prism in the laser receiver, the problem of large space occupation by optical components in the prior art is solved, and the miniaturization of the laser receiver is realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-03-13
AI Technical Summary
Existing laser receivers require external optical components such as filters and reflectors to split and converge light when receiving multi-wavelength mixed optical signals, resulting in a large size that makes it difficult to meet miniaturization requirements.
The beam splitter integrates the functions of beam splitting, converging and receiving optical signals. It uses the beam splitter surface and the reflective surface of the beam splitter to transmit and reflect light signals of different wavelengths respectively. The light signals are then converged by the focusing element and received by the photodiode chip, eliminating the need for external optical components.
It achieves integrated processing of optical signals, reduces the size of the laser receiver, meets the miniaturization requirements, and eliminates the need for additional optical components.
Smart Images
Figure CN223993018U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical communication technology, specifically to a beam splitter prism and a photodiode receiving component with beam splitting function. Background Technology
[0002] When a laser receiver receives a multi-wavelength mixed optical signal, the light should first be split externally before each signal is received by a separate laser receiver. Currently, most light splitting uses filters; the splitting principle can be found in [link to relevant documentation]. Figure 1 A dual-wavelength mixed optical signal 'a' is incident on a first filter 110. The first wavelength optical signal 'a1' in the dual-wavelength mixed optical signal 'a' is transmitted through the first filter 110, while the second wavelength optical signal 'a2' in the dual-wavelength mixed optical signal 'a' is reflected by the first filter 110. The transmitted first wavelength optical signal 'a1' reaches a first condenser lens 140; the second wavelength optical signal 'a2' is reflected to a reflector 130, then reflected again by the reflector 130 to a second filter 120, and transmitted through the second filter 120 to a second condenser lens 150. The first condenser lens 140 is used to focus the first wavelength optical signal 'a1', and the second condenser lens 150 is used to focus the second wavelength optical signal 'a2'. The focused first wavelength optical signal 'a1' and second wavelength optical signal 'a2' are then received by independent laser receivers.
[0003] The above-mentioned existing technologies are currently widely used, but they have the problem of large space occupation, making it difficult to meet the current miniaturization requirements. Utility Model Content
[0004] The purpose of this application is to provide a beam splitter prism and a photodiode receiving component with beam splitting function. The photodiode receiving component of this application integrates the functions of beam splitting, focusing and receiving optical signals, which can meet the requirements of miniaturization.
[0005] On one hand, this application provides a beam splitter prism, which has opposing incident and exit surfaces, as well as a beam splitting surface and a reflecting surface. The beam splitting surface is disposed inside the beam splitter prism and is configured to transmit and reflect two optical signals in a dual-wavelength mixed optical signal incident from the incident surface, respectively. The reflecting surface is configured to change the transmission direction of the reflected optical signal reflected by the beam splitting surface, so that the reflected optical signal and the transmitted optical signal transmitted from the beam splitting surface are transmitted to the exit surface in parallel and at a distance from each other and are output in parallel.
[0006] In some specific embodiments, the emitting surface includes a first bandpass filter surface and a second bandpass filter surface. The first bandpass filter surface and the second bandpass filter surface are respectively disposed in the emitting regions of the transmitted light signal and the reflected light signal on the emitting surface. The first bandpass filter surface is configured to allow only the transmitted light signal to pass through, and the second bandpass filter surface is configured to allow only the reflected light signal to pass through.
[0007] In some specific embodiments, an anti-reflection coating is provided on the incident surface.
[0008] In some specific embodiments, a beam-splitting film is provided on the beam-splitting surface.
[0009] In some specific embodiments, a reflective film is provided on the reflective surface.
[0010] In some specific implementations, the spacing is 250um-1500um.
[0011] In some specific embodiments, the beam-splitting prism is composed of a right parallelepiped prism and a right-angled triangular prism; specifically:
[0012] A beam splitter is constructed by cementing a rectangular face of a right parallelepiped prism with the inclined face of a right-angled triangular prism, and the cemented face is made into a beam splitter. The face of the right parallelepiped prism that is connected to and faces the beam splitter is the incident face. The face opposite the incident face of the right parallelepiped prism is the exit face of the reflected light signal. The face opposite the beam splitter is the reflecting face. The face opposite the incident face of the right-angled triangular prism is the exit face of the transmitted light signal.
[0013] Furthermore, making the glued surface into a beam-splitting surface includes: making a beam-splitting film on the glued surface.
[0014] Furthermore, the exit surface of the reflected light signal is configured to allow only the reflected light signal to pass through.
[0015] Furthermore, the exit surface of the transmitted light signal is configured to allow only the transmitted light signal to pass through.
[0016] Furthermore, an anti-reflection coating is provided on the incident surface.
[0017] Furthermore, a reflective film is provided on the reflective surface.
[0018] Furthermore, the acute angle of the right-angled face of a right-angled triangular prism is equal to the acute angle of the parallelogram face of a right parallelepiped prism.
[0019] Furthermore, the right-angled prism is an isosceles right-angled prism, and the acute interior angle of the parallelogram face of the right parallelepiped prism is 45 degrees.
[0020] On the other hand, this application also provides a photodiode receiving component with beam splitting function, including the aforementioned beam splitting prism, a first focusing element, a second focusing element, a first photodiode chip, and a second photodiode chip; wherein, the first focusing element and the first photodiode chip are arranged sequentially along the transmission optical path of the output transmitted light signal; the second focusing element and the second photodiode chip are arranged sequentially along the transmission optical path of the output reflected light signal.
[0021] Please see Figure 2 The diagram shown illustrates the beam-splitting principle of the photodiode receiving component of this application. Figure 1 Unlike the principle of using filters for beam splitting, this application uses a beam splitter prism 210 for beam splitting. The beam splitting surface 211 within the beam splitter prism 210 separates the dual-wavelength mixed optical signal a into a first-wavelength optical signal a1 and a second-wavelength optical signal a2. The reflecting surface 212 changes the transmission direction of the second-wavelength optical signal a2, making it output parallel to the first-wavelength optical signal a1. Figure 1 Compared to the previous version, the photodiode receiving component of this application integrates the functions of optical signal splitting, focusing and receiving. Since there is no need to lay out optical components such as filters and reflectors, it can meet the requirements of miniaturization.
[0022] Compared with the prior art, the beneficial effects of this application are as follows:
[0023] Existing laser receivers lack optical signal splitting and focusing capabilities, requiring external optical components such as filters and reflectors to achieve these functions. This results in a large footprint and hinders miniaturization. The photodiode receiver component of this application integrates optical signal splitting, focusing, and receiving functions. Furthermore, since it eliminates the need for filters and reflectors, it is more compact, enabling miniaturization and meeting TO packaging requirements. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is the current technology based on the principle of light dispersion using filters;
[0026] Figure 2 This is a schematic diagram illustrating the beam splitting principle of the photodiode receiving component in the embodiment.
[0027] Figure 3 This is a schematic diagram of the specific structure of the photodiode receiving component in the embodiment;
[0028] Figure 4 This is a schematic diagram of the specific structure of the beam-splitting prism in the embodiment.
[0029] Reference numerals: First filter 110, second filter 120, reflector 130, first condenser lens 140, second condenser lens 150; beam splitter prism 210, right parallelepiped prism 210a, right-angle triangular prism 210b, beam splitting surface 211, reflecting surface 212, incident surface 213, first bandpass filter surface 214, second bandpass filter surface 215, first condenser element 220, second condenser element 230, first photodiode chip 240, second photodiode chip 250, base 260; dual-wavelength mixed optical signal a, first wavelength optical signal a1, second wavelength optical signal a2. Detailed Implementation
[0030] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0031] The following will combine Figure 2-4 The specific structure and technical principle of the photodiode receiving component and the beam splitter in the embodiments of this application are described in detail.
[0032] The photodiode receiving component with beam-splitting function in this embodiment includes a beam-splitting prism 210, a first focusing element 220, a second focusing element 230, a first photodiode chip 240, and a second photodiode chip 250. The beam-splitting prism 210 has opposing incident and exit surfaces, a beam-splitting surface 211, and a reflecting surface 212. The beam-splitting surface 211 is disposed within the beam-splitting prism 210 and is configured to transmit two different wavelengths of light signals from the incident dual-wavelength mixed light signal a. The reflective surface 212 is configured to change the transmission direction of the reflected light signal reflected by the beam splitter 211, so that the reflected light signal and the transmitted light signal transmitted from the beam splitter 211 are transmitted to the output surface in parallel and at a distance from each other and are output in parallel; the first focusing element 220 and the second focusing element 230 are used to converge the output transmitted light signal and the reflected light signal, respectively; the converged transmitted light signal and the reflected light signal are received by the first photodiode chip 240 and the second photodiode chip 250, respectively.
[0033] The reflected light signal and the transmitted light signal are parallel to each other and maintain a distance. Generally speaking, a small distance will result in a high manufacturing cost of the beam splitter; a large distance will affect the miniaturization of the component. In order to balance manufacturing cost and ensure miniaturization, the distance in this embodiment is preferably 250um-1500um.
[0034] In this application, a beam-splitting prism 210 is used to split the incident dual-wavelength mixed optical signal a. Specifically, different wavelength optical signals are selectively reflected and transmitted to achieve separation of different wavelength optical signals. Please refer to [link to relevant documentation]. Figure 2 The dual-wavelength mixed optical signal a contains two optical signals with wavelengths of λ1 and λ2. The beam splitting surface 211 of the beam splitter 210 is configured to transmit the optical signal with wavelength λ1 and reflect the optical signal with wavelength λ2, thereby separating the dual-wavelength mixed optical signal a into two optical signals: the first wavelength optical signal a1 and the second wavelength optical signal a2.
[0035] In this embodiment, a first focusing element 220 and a first photodiode chip 240 are arranged sequentially on the transmission optical path of the transmitted light signal output from the beam splitter 210. The transmitted light signal passes through the first focusing element 220 and the first photodiode chip 240 in sequence. The first focusing element 220 is used to converge the transmitted light signal, and the converged transmitted light signal is received by the first photodiode chip 240.
[0036] In this embodiment, a second focusing element 230 and a second photodiode chip 250 are arranged sequentially on the transmission optical path of the reflected light signal output from the beam splitter 210. The reflected light signal passes through the second focusing element 230 and the second photodiode chip 250 in sequence. The second focusing element 230 is used to focus the reflected light signal, and the focused reflected light signal is received by the second photodiode chip 250.
[0037] In this embodiment, the transmitted light signal is... Figure 2 The first wavelength optical signal a1 in the light, the reflected light signal is... Figure 2 The second wavelength optical signal a2 in the signal.
[0038] In this embodiment, the photodiode receiving component further includes a base 260, on which the first photodiode chip 240 and the second photodiode chip 250 are mounted.
[0039] In this embodiment, the beam-splitting surface 211 achieves selective reflection and transmission of light signals of different wavelengths through a beam-splitting film. A beam-splitting film is a common optical thin film, and common beam-splitting film materials include metallic materials such as aluminum, silver, and gold, and dielectric materials such as silicon dioxide, titanium dioxide, and tantalum pentoxide. This application does not limit the beam-splitting film material. Different beam-splitting characteristics can be obtained by adjusting the composition, thickness, and / or structure of the beam-splitting film. In this embodiment, by adjusting the composition, thickness, and / or structure of the beam-splitting film, the beam-splitting surface 211 is configured to transmit light signals with wavelengths of 1260nm-1280nm and reflect light signals with wavelengths of 1295nm-1330nm.
[0040] In this embodiment, the reflective surface 212 achieves its reflective function through a reflective film. Common reflective film materials include metallic materials such as aluminum, silver, and gold, and dielectric materials such as silicon dioxide, titanium dioxide, and tantalum pentoxide. By adjusting the composition, thickness, and / or structure of the reflective film, the reflective surface 212 is configured to reflect the second wavelength light signal a2.
[0041] As a preferred embodiment, an antireflection film is provided on the incident surface 211. The antireflection film can reduce the reflection of the incident light signal and increase the transmittance of the light signal. Common antireflection film materials include tantalum pentoxide, silicon dioxide, and titanium dioxide.
[0042] In a preferred embodiment, the exit surface is parallel to the incident surface 211, and the exit surface further includes a first bandpass filter surface 214 and a second bandpass filter surface 215. The bandpass filter surface is used to allow only optical signals of specific wavelengths to pass through, while blocking optical signals of other wavelengths.
[0043] Furthermore, the first bandpass filter surface 214 and the second bandpass filter surface 215 are respectively disposed in the emission regions of the transmitted light signal and the reflected light signal on the emission surface. The first bandpass filter surface 214 is configured to allow only the transmitted light signal to pass through, and the second bandpass filter surface 215 is configured to allow only the reflected light signal to pass through. Using the first bandpass filter surface 214 and the second bandpass filter surface 215 can prevent crosstalk between the two types of emitted light signals.
[0044] The first bandpass filter surface 214 and the second bandpass filter surface 215 can achieve selective filtering function through filter films. Common filter film materials include silicon dioxide, titanium dioxide, tantalum pentoxide, etc.
[0045] To ensure the parallelism of the output transmitted light signal and the reflected light signal, and to facilitate precise control of the spacing between the output transmitted light signal and the reflected light signal, this embodiment provides a preferred structure for the beam splitter.
[0046] Please see Figure 4 The beam splitter 210 is composed of a right parallelepiped prism 210a and a right-angled triangular prism 210b. The right parallelepiped includes three pairs of opposite faces, and two of the opposite faces in each pair are parallel and equal. One pair of opposite faces is a parallelogram, and the other two pairs of opposite faces are rectangles. Specifically, a rectangular face of the right parallelepiped prism 210a is glued to the inclined face of the right-angled triangular prism 210b to form the beam splitter prism 210. The glued surface is made into a beam splitter 211, that is, a beam splitter film is made on the glued surface to obtain the beam splitter 211.
[0047] In this preferred structure of the beam splitter prism, the side of the right parallelepiped prism 210a that is connected to and faces the beam splitter 211 is used as the incident surface 213, the opposite side of the incident surface 213 is used as the second bandpass filter surface 215, and the opposite side of the beam splitter 211 in the right parallelepiped prism 210a is used as the reflecting surface 212.
[0048] When designing the dimensions and angles of the right parallelepiped prism 210a, it should be ensured that: the dual-wavelength mixed light signal a is transmitted to the beam splitter 211 after being incident perpendicularly to the incident surface 213; the second wavelength light signal a2 in the dual-wavelength mixed light signal a is reflected by the beam splitter 211 and reaches the reflecting surface 212; and after being reflected by the reflecting surface 212, it is output from the second bandpass filter surface 215.
[0049] The straight parallelepiped prism 210a is used to horizontally deflect the second wavelength light signal a2 in the incident dual-wavelength mixed light signal a without changing its direction. Here, "without changing its direction" means that the incident and outgoing directions of the second wavelength light signal a2 are parallel.
[0050] In this preferred structure of the beam splitter, the side of the right-angle triangular prism 210b opposite to the incident surface 213 is used as the exit surface, namely the first bandpass filter surface 214. The dual-wavelength mixed optical signal a is incident from the incident surface 213 and transmitted to the beam splitter 211. The first wavelength optical signal a1 in the dual-wavelength mixed optical signal a is transmitted from the beam splitter 211 and transmitted to the first bandpass filter surface 214 and output from the first bandpass filter surface 214.
[0051] Furthermore, the acute angle of the right-angled facet of the right-angled prism 210b is equal to the acute angle of the parallelogram facet of the right parallelepiped prism 210a. In one specific embodiment, the right-angled prism 210b is preferably an isosceles right-angled prism, that is, the two acute angles of its right-angled facet are 45 degrees; and the acute interior angle of the parallelogram facet of the right parallelepiped prism 210a is preferably 45 degrees. The right-angled facet of the right-angled prism 210b refers to a right-angled triangular facet.
[0052] The working principle of the above photodiode receiving component with beam-splitting function is as follows:
[0053] A dual-wavelength mixed optical signal 'a' enters the beam-splitting prism 210 from the incident surface 213 and is transmitted to the beam-splitting surface 211. The first wavelength optical signal a1 and the second wavelength optical signal a2 in the dual-wavelength mixed optical signal 'a' are transmitted and reflected by the beam-splitting surface 211, respectively. The first wavelength optical signal a1 passes through the beam-splitting surface 211 and is output from the first selective filter surface 214. The second wavelength optical signal a2 is reflected to the reflecting surface 212, which uses reflection to change the transmission direction of the second wavelength optical signal a2 to be parallel to the first wavelength optical signal a1, and outputs it from the second selective filter surface 215. The output first wavelength optical signal a1 and the second wavelength optical signal a2 are transmitted parallel to each other and maintain a distance. After being converged by the first focusing element 220 and the second focusing element 230, respectively, they are received by the first photodiode chip 240 and the second photodiode chip 250. After receiving the optical signals, the first photodiode chip 240 and the second photodiode chip 250 generate photocurrent based on the photoelectric effect and output it, thereby achieving the separation of different wavelength optical signals.
[0054] If existing technology is used to achieve the separation and reception of the dual-wavelength mixed optical signal 'a' in this embodiment, two TO-46 chips plus external beam splitting and focusing optical components are required. However, the photodiode receiving component of this application integrates beam splitting, focusing, and receiving functions, eliminating the need for external beam splitting and focusing optical components. Only one TO-46 chip is needed to achieve the separation and reception of the dual-wavelength mixed optical signal 'a', thus achieving miniaturization.
[0055] Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of this application, all of which fall within the scope of protection of this application.
Claims
1.A light splitting prism, characterized in that: the light splitting prism is provided with opposite incident surface and emergent surface, and light splitting surface and reflecting surface; the light splitting surface is arranged in the light splitting prism and is configured to transmit and reflect two light signals in a mixed light signal of double wavelengths respectively; the reflecting surface is configured to change the transmission direction of the reflected light signal reflected by the light splitting surface, so that the reflected light signal and the transmitted light signal transmitted from the light splitting surface are parallel to each other and keep a distance to be transmitted to the emergent surface and output in parallel. 2.The light splitting prism of claim 1, characterized in that: the emergent surface comprises a first band-pass filter surface and a second band-pass filter surface, the first band-pass filter surface and the second band-pass filter surface are arranged on the emergent surface in the emergent area of the transmitted light signal and the reflected light signal respectively, the first band-pass filter surface is configured to allow only the transmitted light signal to pass through, and the second band-pass filter surface is configured to allow only the reflected light signal to pass through. 3.The light splitting prism of claim 1, characterized in that: the incident surface is provided with an anti-reflection film. 4.The light splitting prism of claim 1, characterized in that: the light splitting surface is provided with a light splitting film. 5.The light splitting prism of claim 1, characterized in that: the reflecting surface is provided with a reflecting film. 6.The light splitting prism of claim 1, characterized in that: the distance is 250um-1500um. 7.The light splitting prism of claim 1, characterized in that: the light splitting prism is composed of a straight parallelepiped prism and a right-angle prism; specifically: a rectangular surface of the straight parallelepiped prism and an inclined surface of the right-angle prism are glued to form the light splitting prism, and the glued surface is made into the light splitting surface; a surface of the straight parallelepiped prism connected with the light splitting surface and opposite to the light splitting surface is the incident surface, an opposite surface of the incident surface in the straight parallelepiped prism is the emergent surface of the reflected light signal, an opposite surface of the light splitting surface in the straight parallelepiped prism is the reflecting surface, and a surface of the right-angle prism opposite to the incident surface is the emergent surface of the transmitted light signal. 8.The light splitting prism of claim 7, characterized in that: the glued surface is made into the light splitting surface comprises: a light splitting film is made on the glued surface. 9.The light splitting prism of claim 7, characterized in that: the emergent surface of the reflected light signal is configured to allow only the reflected light signal to pass through. 10.The light splitting prism of claim 7, characterized in that: the emergent surface of the transmitted light signal is configured to allow only the transmitted light signal to pass through. 11.The light splitting prism of claim 7, characterized in that: the incident surface is provided with an anti-reflection film. 12.The light splitting prism of claim 7, characterized in that: the reflecting surface is provided with a reflecting film. 13.The light splitting prism of claim 7, characterized in that: the acute angle of the right-angle surface of the right-angle prism is equal to the acute angle of the parallelogram surface of the straight parallelepiped prism. 14.The light splitting prism of claim 7, characterized in that: the right-angle prism is an isosceles right-angle prism, and the acute angle of the parallelogram surface of the straight parallelepiped prism is 45 degrees. 15. A photodiode receiving assembly with light splitting function, characterized in that: The photodiode receiving assembly comprises the light splitting prism according to any one of claims 1-14, a first light collecting element, a second light collecting element, a first photodiode chip and a second photodiode chip; wherein the first light collecting element and the first photodiode chip are sequentially arranged along a transmission light path of the output transmitted light signal; and the second light collecting element and the second photodiode chip are sequentially arranged along a transmission light path of the output reflected light signal.